Field of the Invention
The present invention relates to an image processing apparatus and method, and to an image capturing apparatus.
Description of the Related Art
In recent years, television standards have been changing from a resolution of 1920 horizontal pixels by 1080 vertical pixels (1920×1080 pixels) called full high definition to a resolution of 3840×2160 pixels called 4k2k, which is four times the pixel number of HD. Moreover, as a next generation standard after 4k2k, there is also a standard called 8k4k or super high definition, and according to this standard, the pixel number is as much as 7680×4320 pixels.
On the other hand, with the increase in the pixel number, the total number of defective pixels in CMOS sensors has also been increasing. In general, in order to correct signals of defective pixels, defective pixel information is stored in the memory of the camera body, and signals of the defective pixels are corrected using this data at the time of shooting. However, the memory capable of storing the defective pixel information is limited, and in the case where a large number of defective pixels exist, the information for all of the defective pixels cannot be stored in the memory.
Japanese Patent Laid-Open No. 07-059011 discloses a technique for efficiently using a limited memory by comparing the data of a defective pixel stored in the memory with the data of a newly detected defective pixel, and storing the data of the defective pixel having the higher level in the memory.
However, in Japanese Patent Laid-Open No. 07-059011, defective pixels having a high level can be corrected, but there are cases where the data of defective pixels having a low level cannot be stored in the memory, and thus these defective pixels cannot be corrected.